WO94/20460 describes angiotensin II compounds of the following formula: wherein X can be a number of substituents and Het can be a nitrogen-containing heterobicycle. However, WO94/20460 does not suggest Factor Xa inhibition or exemplify compounds like those of the present invention.
WO96/12720 describes phosphodiesterase type IV and TNF production inhibitors of the following formula: wherein X can be oxygen and R2 and R3 can a number of substituents including heterocycle, heterocycloalkyl, and phenyl. However, the presently claimed compounds do not correspond to the compounds of WO96/12720. Furthermore, WO96/12720 does not suggest Factor Xa inhibition.
WO98/52948 describes inhibitors of ceramide-mediated signal transduction. One of the types of inhibitors described is of the following formula: wherein Y1 can be N—R6, R6 can be unsubstituted aryl-alkyl or unsubstituted heterocyclic-alkyl and R1 can be a substituted aryl group. WO98/52948 does not mention factor Xa inhibition or show compounds like those of the present invention.
U.S. Pat. Nos. 3,365,459 and 3,340,269 illustrates anti-inflammatory inhibitors of the following formula: wherein A is 2-3 carbon atoms, X can be 0, and R1 and R3 can be substituted or unsubstituted aromatic groups. Neither of these patents, however, exemplify compounds of the present invention.
Activated factor Xa, whose major practical role is the generation of thrombin by the limited proteolysis of prothrombin, holds a central position that links the intrinsic and extrinsic activation mechanisms in the final common pathway of blood coagulation. The generation of thrombin, the final serine protease in the pathway to generate a fibrin clot, from its precursor is amplified by formation of prothrombinase complex (factor Xa, factor V, Ca2+ and phospholipid). Since it is calculated that one molecule of factor Xa can generate 138 molecules of thrombin (Elodi, S., Varadi, K.: Optimization of conditions for the catalytic effect of the factor IXa-factor VIII Complex: Probable role of the complex in the amplification of blood coagulation. Thromb. Res. 1979, 15, 617-629), inhibition of factor Xa may be more efficient than inactivation of thrombin in interrupting the blood coagulation system.
Therefore, efficacious and specific inhibitors of factor Xa are needed as potentially valuable therapeutic agents for the treatment of thromboembolic disorders. It is thus desirable to discover new factor Xa inhibitors.